1. Field of the Invention
The present invention relates to a motor-operated damper device in which an opening section is opened and closed by a baffle that is driven by a motor.
2. Related Background Art
A motor-operated damper device 150 that may be used in a refrigerator or other similar devices is shown in FIGS. 10 and 11. The motor-operated damper device 150 includes pivot shafts 151, a baffle 152 that is rotatable about the pivot shafts 151 and a driving mechanism section 153 equipped with a motor for driving the baffle 152. The baffle 152 and the driving mechanism section 153 are disposed on both sides of the pivot shafts 151. While looseness is provided at the baffle 152 and among members within the driving mechanism section 153, a leaf spring (omitted from the drawing) that normally pushes the baffle 152 toward a closing direction is provided at the back of the baffle 152 in order to increase the air-tightness between the baffle 152 and a frame 154. In order to further improve the air-tightness of the baffle 152, a soft tape 155 is attached to a surface of the baffle 152 that abuts against the frame 154 such that, when the baffle 152 is at a closing position, the frame 154 sinks in the soft tape 155.
In the motor-operated damper device 150 shown in FIGS. 10 and 11, the rotational torque of the motor is converted through a cam mechanism into a thrust-direction torque of a spindle, and the baffle 152 is driven by the thrust-direction torque of the spindle to rotate about the rotation pivots 151 as a rotation center. Accordingly, the conventional motor-operated damper device 150 is provided with a structure in which appropriate looseness is given, in consideration of precision of each of components, to the components when the baffle 152 is closed, and the baffle 152 is pressed down by the leaf spring against the frame 154.
Consequently, the conventional motor-operated damper device 150 needs a leaf spring with a substantially large spring force in order to securely provide the air-tightness. As a result, the baffle 152 may be pressed against the soft tape 155 with an excessively strong force such that the frame 154 sinks excessively into the soft tape 155. As opening and closing operations of the baffle 152 are repeated, the soft tape 155 permanently deforms, and looses its softness, such that the baffle 152 can no longer securely provide the required air-tightness.